Tire patch



Oct. 6, 1931. Y P. E. HAwKlNsoN 1,826,073V

TIRE PATCH Original Filed Aug. 25' 1925 maining carcass.

ldatented ct. 6, 1931 sirnrs PAUL E. EAWKINSON,

l@ ei i 0F MINNEAAPOLIS, MINNESOTA, ASSIGNOR TO KEHAWKE MAN'U TIRE PATCH @riginal application tiled August 25', 1925, Serial No. 52,474. Patent No. 1,697,955, dated January 8, 1929.

' Divided and this application led December 16, 1927. Serial No. 240,353.

My invention relates to an improved tire patch and is an improvement upon the invention set 'forth in my Patent No. 1,436,394 dated November 21, 1922.

rlhis application is a division of my copending application, Serial No. 52,474, tiled August 25, 1925, which matured into Patent No. 1,697,955, granted January 8, 1929, in whichlthe method of making the herein described patch is claimed. The machine by which the present patch isvmade is fully disclosed and claimed in my Patent No. 1,759,- 507, granted May20, 1930, which was issued 'on an application which was also a division of said application Serial No. 52,474.

in the usual method heretofore employed in making patches 4for repairing pneumatic tire casings, as set iorth in my above mentioned patent, it has been the practice to strip or pull the desired number of plies or layers of fabric and interposed rubber from the carcass of a used tire; cut the removed layers or plies to the desired shape (usually round) and then slrive the edge so that a neat or dat joint may be made withl the casing ci the tire to be repaired. When the plies for patch material are removed from the tire carcass in this manner, the separation is usually uneven, the interposed layer ci rubber adhering in places to the surface of the removed plies and in other places to the rerl`he surfaces oil the patch material are therefore apt tb be uneven, covered with a layer-of rubber in some portions and substantially ree of rubber in other ortions. Because oi this uneven cleavage when the pulling method of separation is employed, it surfaces of the patch material to remove any traces ci the rubber layer adhering thereto and to thereby give the surfaces a uniform exposure of abric. Unless the buding of this surplus rubber from the surfaces et the patch is very carefully done the :labric is apt to become loosened and parts thereof removed, thus reducing it's strength to some extent. The use of such fabric faced ypatchesin repairing tires accordino` to the `method set iorth in my previously mentimed-'patent ordinarily requires that, be-I has been the practice to bud the fore the patch is placed one or both of its fabric faces be covered or coated with a thin layer of gum rubber or similar material. rlhese extra steps of removing the uneven layer of original rubber and then applying the thin-and uniform coating of new rubber adds to the labor and expense of making the patches. Furthermore, this application of uncured rubber to the surfaces of material does not always produce a thorough union between the rubber and the buffed fabric, such, Ifor example,'as exists between the layers of fabricv and vulcanized rubber of a tire casing. lt has also been found that, in pulling the patch'material from the carcass, the fabric at the plane of cleavage is oftentimes injured because o the tendency to deform and tear the fabric and' to stretch and displace the strands of which it is composed.

'.lhe principal object of my present invention is to provide a patch having the same general type and characteristics of that disclosed inmy previously mentioned patent, but which is covered on either or both of its surfaces with a thin and uniform layer of the original interposed layer of vulcanized rubber.

l prefer to take the patch material from used tires because the plies are irmly welded or cemented together, alll of the stretch has been removed from the fabric so that the patch will remain in position and will not bulge, the material is formed to the shape of the tire to be repaired, and furthermore the materials ordinarily used in tire manufacture are of a better grade and quality than can be obtained upon the market merely for tire repair purposes. i

A. further object is to provide an improved .tire patch, which is strong, properly shaped and which may be economically manufactured.

Other objects will appear from the following description in which:

Figurel is a section of a used tire casing Vshowing the portion thereof which is used in making my improved patch.

Figures 2 and -3 are enlarged sections to 'diderent scales'- of portions of the casing the patch showin how the patch material is cut from the use tire casing.

Figure 4 is a side elevation of my improved patch, part thereof being shown in section.

Accordin to the method of making my 1mproved patc which is fully disclosed in my aforesaid co-pending application, a usedtire casing 6 having the usual tread portion 8 and beads l0 is flattened out and the bead portions cut oi along the lines 12--12 shown in .Fig` ,ure 1. The casin is also transversely severed so as to form a single strip. The casing, of course, com rises alternate layers of fabric cord and ru ber.' The structure is best illustrated in Figure 3 where reference character 14 indicates the innermost layer of rubber; 16, the innermost layerof fabric; 18, 20, 22, 24, 26, intermediate layers of rubber; and 28, 3.2, 34 and36, the-layers or plies of the cord a ric.

As hasbeen above pointed out, it is highly desirable to obtain a patch havingitsI external surfaces covered with layers of the original rubber of the casing. 'lo accomplish this purpose the patching material is made by cutting through the intermediate layers of rubber.' By performing this operation properly the cut may be made through the center of this intermediate layer of rubber, thus leavingvthe adjacent plies of fabric covered with their original rubber. i

In Fi re 2, I have diagrammatically illustrated t e method by which the tire patching material is severed from the tire casing. An

" endless band' knife 38 is guided in a kWedgeshaped member 40 and held against trans- .verse movement by a plurality ofrollers 42.

which are suitably mounted on the guide member 40. The knife 38 is movedcontinw ously in one direction in cu-ttin through the rubber layer and the caslng fe to the knife. The knife is quite blunt and suciently flexible, and the mounting therefor permits sut ficient play so `that the knife will follow a substantially median plane through the rubber la er and not cut into the fabric. This is higlily desirable since it is found'that the cut cannot be made with mathematical exactitude because of the irregularities in the distanceof the plies of fabric from the inner surface of a tire casing. If a rigid knife is rigidly guided andr set to cut a certain dis-iy tance from rthe 'surface of the inside of the i tire casing (when flattened out thel knifey would cut through portions of t e fabric as well as through the above-mentloned variationsin the distance between the cord fabric and the inner surface of ther tire casing. 1

In Figure 2, the kni e is shown as vtaking ya cut of two plies from a used tire Casin and i portions of therrubber du@ a patches may be made more than two plies thick, or in certain instances a patch one py dull finish, that is, it is nota glazed su ace,

but, as a whole, is comparatively smooth".

`While the patching material thus severed from the tire casing may be cut into various shapes and used in any manner desired, I prefer to form patches of graduated size and circular in form, as described in my abovementioned patent.

' In Figure 4,I yhave shown such a patch 44 in elevation. It will be noted that the outer edge surfaces have been skived at,46. By complementally skiving the internal surfaces of t 1e ,casinar to be repaired with the atch, a strong and smooth patch is obtaine By making thepatches of circu'lar form and standard'dlmensions, the patches may be prepared in advance and applied to the casmgs which have been prepared to receive standard sized patches.

While I have shown and described a particular embodiment of my invention, I do not wish my invention to"be limited to the specific features thereof since various modifications thereof may be madewithout 'departure from the yprinciples herein disclosed.' I therefore.

desire the scope of'my invention to be limited onl bythe claimwhichfollows; i 'f claimt: i g As a new article yof manufacture, a tire repair sheet or shoe formed from an old tire casing and comprising a` sluralityof fabric pliesunited byl vulcanize 'rubber and rovided on its convex side with a vulcamzed rubber film filling the spacesbetween the threads of the outer fabric ply and formin a surfacethat is relativel smooth and' unlform as characterized by being cut from the tire casing, substantiall as described.y

Inwitness whereof, hereunto subscribe my name this 13th dayof December 1927. A PAUL n. HAWKISON.

in Figure 3 the dot and dashli'nes in icate i the cuts which'may be takentor provide three pieces of tire patching material ,from ya casing having six plies of fabric.l If desired, the

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